Yeah, sounds like the rev limiter to me. First couple times I hit it I thought the same thing. My C5Z is the first car to ever have some sort of device like that. Well at least in a case where I would actually ever hit those high rpms.
I believe that hitting the rev limiter shuts off the fuel supply, so that is exactly the effect you would get.
Try keeping your eye on your tachometer to see if you are red-lining it when that problem shows up.